1,724 research outputs found

    Simple fence modification increases land movement prospects for freshwater turtles on floodplains

    Get PDF
    Installing conservation fences to prohibit feral animal access to wetlands can become a barrier for non-target species of interest. We collected 161 turtles (Chelodina rugosa, Emydura subglobosa worrelli, Myuchelys latisternum) from twenty floodplain and riverine wetlands during post-wet (June–August) and late-dry season (November–December) surveys (2015–2018) in northern Australia. Wetlands were fenced (150 × 150 mm square, 1.05 m high wire mesh) or unfenced around the wet perimeter. Ninety-seven percent of individuals caught in either fenced or unfenced wetlands had a shell carapace width greater than mesh width, of these 44 (46%) were captured inside fenced wetlands, while 50 were caught in unfenced wetlands. The remaining 35 turtles were smaller than 150 mm and would likely pass easily through fence mesh. Sixty-five turtles partook in a fencing manipulative experiment. Turtles with carapace widths wider than mesh often successfully escaped through fences by lifting one side of their shell and passing diagonally through the mesh. In a second experiment where a piece of vertical wire (1500 × 300 mm) was removed, turtles located ‘gates' after prospecting and fitting through meshing areas that were too small to pass. Ninety-two percent of turtles were able to locate and pass through gates, while 8% failed to locate a gate after 2 h. Gates applied every 4 m showed an 83% passage rate, every 2 m was 91%, and every 1 m was 100%. Combing field and manipulative experiments revealed that large turtles will prospect and move along a fence until they find suitable passage, which has important consequences when considering that gates could be easily retrofitted to existing sites, as well in new fencing programs, which has enormous positive conservation benefits for turtles in an already challenging and changing floodplain environment

    Nurse education leaders' perspectives on the teaching of numeracy to undergraduate nursing students : a qualitative research study

    Get PDF
    Aim The aim of this study was to explore the perspectives of nurse education leaders of Australian undergraduate nursing degrees on the teaching of nursing numeracy and how the Australian Nursing & Midwifery Accreditation Standards influence curriculum development. Background Nurses’ numeracy skills are reportedly deficient worldwide, posing a significant threat to patient safety. This is an issue for the education of undergraduate nurses and thus for the nursing profession. The international literature reveals a heterogeneous blend of learning approaches, but it is unclear which approaches are best suited to improve the numerical calculation ability of nurses. In the Australian context, there are no accreditation standards referring to numeracy, therefore, it is important to discover how nurse education leaders’ design and implement the teaching of numeracy. Design A qualitative approach using thematic analysis was employed. The setting was Australian universities that delivered an accredited undergraduate nursing degree leading to nursing registration. Methods Purposive sampling was used to recruit 17 nurse education leaders of Australian undergraduate nursing degrees. Individual, semi-structured virtual interviews were conducted between November 2022 and January 2023. Interview data were analysed using Braun and Clarke’s (2006) six phases of thematic analysis. Findings Five themes emerged from the analysis: (i) indistinct accreditation standards, (ii) teaching basic maths for clinical applications, (iii) a range of bespoke teaching approaches (iv) we’re nurses, not numeracy educators and (v) assumptions about an unprepared cohort. Conclusion The leaders of undergraduate nursing degrees assumed that nursing students would have proficiency in numeracy skills on entering university. However, this was not the case, hence numeracy was an essential skill that needed to be taught to the undergraduate nursing students. Lack of direction from the accreditation council led to the existence of various curricula and an array of approaches to teaching numeracy and medication calculations, which challenged nursing academics who did not consider themselves numeracy educators. This study makes a novel contribution to knowledge, teaching and practice in undergraduate nursing numeracy curricula

    NDE for Characterizing Oxidation Damage in Reinforced Carbon-Carbon

    Get PDF
    In this study, coated reinforced carbon-carbon (RCC) samples of similar structure and composition as that from the NASA space shuttle orbiter s thermal protection system were fabricated with slots in their coating simulating craze cracks. These specimens were used to study oxidation damage detection and characterization using NDE methods. These specimens were heat treated in air at 1143 and 1200 C to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1 to 3 mm. Single-sided NDE methods were used since they might be practical for on-wing inspection, while x-ray micro-computed tomography (CT) was used to measure cavity sizes in order to validate oxidation models under development for carbon-carbon materials. An RCC sample having a naturally-cracked coating and subsequent oxidation damage was also studied with x-ray micro-CT. This effort is a follow-on study to one that characterized NDE methods for assessing oxidation damage in an RCC sample with drilled holes in the coating. The results of that study are briefly reviewed in this article as well. Additionally, a short discussion on the future role of simulation to aid in these studies is provided

    Nondestructive Evaluation (NDE) for Characterizing Oxidation Damage in Cracked Reinforced Carbon-Carbon

    Get PDF
    In this study, coated reinforced carbon-carbon (RCC) samples of similar structure and composition as that from the NASA space shuttle orbiter's thermal protection system were fabricated with slots in their coating simulating craze cracks. These specimens were used to study oxidation damage detection and characterization using nondestructive evaluation (NDE) methods. These specimens were heat treated in air at 1143 C and 1200 C to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1 to 3mm. Single-sided NDE methods were used because they might be practical for on-wing inspection, while X-ray micro-computed tomography (CT) was used to measure cavity sizes in order to validate oxidation models under development for carbon-carbon materials. An RCC sample having a naturally cracked coating and subsequent oxidation damage was also studied with X-ray micro-CT. This effort is a follow-on study to one that characterized NDE methods for assessing oxidation damage in an RCC sample with drilled holes in the coating

    The constraints as evolution equations for numerical relativity

    Full text link
    The Einstein equations have proven surprisingly difficult to solve numerically. A standard diagnostic of the problems which plague the field is the failure of computational schemes to satisfy the constraints, which are known to be mathematically conserved by the evolution equations. We describe a new approach to rewriting the constraints as first-order evolution equations, thereby guaranteeing that they are satisfied to a chosen accuracy by any discretization scheme. This introduces a set of four subsidiary constraints which are far simpler than the standard constraint equations, and which should be more easily conserved in computational applications. We explore the manner in which the momentum constraints are already incorporated in several existing formulations of the Einstein equations, and demonstrate the ease with which our new constraint-conserving approach can be incorporated into these schemes.Comment: 10 pages, updated to match published versio

    Analog Radio-over-Fiber Supported Increased RAU Spacing for 60GHz Distributed MIMO employing Spatial Diversity and Multiplexing

    Get PDF
    The improvements in coverage through spatial diversity and increased data rates through spatial multiplexing using a distributed Multiple-Input Multiple-Output (MIMO) system are important targets for future wireless communications. Here, the appropriate separation of Remote Antenna Units (RAUs) at several user locations in a millimeter-wave system is demonstrated. An analog Radio over Fiber (RoF) fronthaul is used to achieve flexible spacing of distributed RAUs and transports two Gb/s data streams over 2.2km of fiber and up to 8m of 60 GHz wireless transmission distance. A performance comparison is performed between Single-Input Single-Output (SISO) and MIMO operation using different antenna spacing and transmission distance. Results show that the wider RAU spacing enabled by the RoF distribution provides improved results at longer distances, for both spatial diversity and for spatial multiplexing. Verification of a method for measuring each channel coefficient individually and using subsequent MIMO processing on these coefficients, enables an extension to the results showing the feasibility of 30m indoor transmission
    • 

    corecore